Cooling radiator having liquid cooling

ABSTRACT

The invention relates to a cooling radiator ( 1 ), comprising an upper accumulator ( 2 ), a lower accumulator ( 3 ), and at least one sub-module ( 4 ) consisting of cooling elements that are respectively connected to the upper accumulator ( 2 ) and/or the lower accumulator ( 3 ) by means of individual manifolds ( 5 ), wherein the sub-modules ( 4 ) are provided with pipes ( 6 ) that have ribs ( 7 ) on the exterior sides thereof, characterized in that the sub-modules ( 4 ) are arranged vertically and transversely to the longitudinal direction of the accumulators ( 2, 3 ) and the pipes ( 6 ) of the sub-modules ( 4 ) are arranged parallel to and at a distance ( 22 ) from one another to allow air to pass therebetween.

FIELD OF THE INVENTION

The invention relates to a cooling radiator, particularly to a radiator of a container of an active transformer part, where the cooling radiator has cooling elements through which cooling fluid heated in the active part flows from above, under the effect of gravity, through a primary manifold, downward to a secondary manifold, and the cooled fluid gets back into the transformer via the another secondary manifold, and at least one cooling radiator is set at a spacing from or directly on the transformer or its boiler.

Cooling radiators of this type comprise, in addition to the upper and the lower primary manifolds, at least one partial module of cooling elements that are connected with the upper or lower primary manifold by respective secondary manifolds, and the submodules have tubes that are each provided with external ribs.

STATE OF THE ART

The cooling elements of transformers or other electrical devices consist of flat cooling elements through which oil generally flows as a cooling fluid, or of corrugated sheet metal, as known from DE 10 2009 015 377. The cooling radiators that consist of multiple such cooling elements put together or connected in series with one another or one behind the other are structured as a welded construction. In order to increase their useful lifetime, they are coated using complicated dipping processes or are hot-dip galvanized.

In contrast, production is supposed to be simplified, while simultaneously allowing a gas-tight and oil-tight connection of the cooling elements with the collectors, and, in particular, the heat transfer or heat transport is supposed to be improved.

OBJECT OF THE INVENTION

It is therefore an object of the invention to make a cooling radiator available that has a simple structure, on the one hand, and, on the other hand, guarantees increased heat transfer, at the same outside dimensions of the cooling radiator as a whole. This object is attained according to the invention, with a cooling radiator comprising the characteristics of claim 1. Advantageous embodiments of the invention are presented in the dependent claims.

SUMMARY OF THE INVENTION

According to the invention, the submodules extend perpendicular and transverse to the longitudinal direction of the primary manifolds, with the tubes of the submodules being disposed parallel to and at a spacing from one another, for air passage. In this way, a cooling radiator is created that allows particularly good air passage through the cooling radiator as a whole and at the cooling elements, because it is composed of multiple cooling elements that follow one another or follow behind one another in series, with an air gap relative to one another, inserted into the space between the upper primary manifold and the lower primary manifold.

Thus, all the cooling elements of the cooling radiator preferably contribute to heat transfer from the cooling medium, preferably oil, flowing through the cooling radiator, to the ambient air that flows through the cooling radiator. In the end result, particularly great energy dissipation of up to 38.00 kW/h, preferably up to 39.80 kW/h, is brought about with a cooling radiator having a width of up to 540 mm, preferably up to 520 mm, and a height of up to 2 m, preferably up to 1.80 m. A cooling radiator having a height of 0.5 m to as much as 3.60 m is preferred. At optimal cross sections of both the upper and the lower primary manifold, and of the tubes of the respective submodules, a flow-through amount of oil through the cooling radiator of up to 2700 kg/h, preferably up to 2800 kg/h, can be achieved.

As experiments have confirmed, the fluid, particularly oil, flowing through the tubes from top to bottom, with the best cooling effect, experiences the least resistance if an optimized cross section of the elements of the cooling radiator is maintained. Because only the least possible resistance occurs, the system can work with free convection; no pump is required.

The cooling radiator is therefore present as a compact complete unit, which consists of as many submodules as desired, set at a spacing from one another, connected with the primary manifolds by the individual secondary manifolds. The complete cooling radiator and its submodules can have ambient air flowing around them completely, both in the transverse and in the longitudinal direction, if necessary supported by blowersfans. In this way, the cooling or the heat transportheat transfer is maintained very efficiently.

A preferred suggestion provides that the tubes and also the primary manifolds, preferably the upper and the lower primary manifold, and also the individual secondary manifolds, consist of a material or material that can be extruded, such as, in particular, aluminum or aluminum alloys, magnesium or similar light metals suitable for extrusion. These materials have good heat transfer properties, on the one hand, and on the other hand are corrosion-resistant because of the oxide layers they form, so that varnishing or similar coating or surface treatment can be eliminated, and furthermore they can be produced in simple manner, namely preferably extruded with any desired shape.

The openings required for connecting the individual components of the cooling radiator are preferably produced in precise manner, by milling or laser machining, so that precise joining locations for microjoining can be achieved, preferably by means of laser welding, with a gas-tight or oil-tight connection.

It is preferred if every submodule comprises up to twelve, preferably up to ten tubes. In this way, a cooling radiator is produced whose active surface can be adapted to the properties required for the cooling radiator with particularly simple means and, if necessary, around which the ambient air can flow completely.

In this connection, it is also preferred if the tubes of the respective submodules have a flattened, preferably rectangular cross section, particularly a rectangular cross section with rounded corners. It is particularly preferred if such tubes have at least one inner partition, preferably two inner partitions. In this connection, the width of the tubes is preferably up to 130 mm, more preferably up to 120 mm. In particular, it is preferred if the spacing between the tubes, relative to one another, per submodule, is up to 30 mm, preferably up to 27 mm. In this way, a cooling radiator is created that allows sufficient flow of cooling media such as oil through the tubes of each submodule, on the one hand, and on the other hand makes tubes having sufficient shape stability available. Ultimately, an optimal air passage through the cooling radiator as a whole is brought about by means of the selection of the preferred spacing between the tubes, thereby making it possible to optimize the cooling output.

It is furthermore preferred if the ribs provided on the outside of the tubes are longitudinal ribs, which preferably extend over the entire length of the tubes, thereby essentially over the entire length of the cooling radiator as a whole. It is particularly preferred if up to 15, extremely preferably up to twelve longitudinal ribs per tube are provided. In this connection, it is particularly preferred if the longitudinal ribs have a height, thereby an expanse from the outside of the tube in an outward direction, of up to 15 mm, preferably up to 12 mm. The spacing between the longitudinal ribs, relative to one another, should be up to 25 mm, preferably up to 20 mm, in order to thereby not only guarantee an active surface for the cooling radiator with great heat dissipation, but rather, at the same time, to also optimize the transfer of heat from the cooling medium to the ambient air that flows around and through the cooling radiator.

In a further embodiment of the invention, it is preferred if up to ten, preferably up to eight submodules are provided in the cooling radiator. These submodules, which are connected with one another, in each instance, by an upper and a lower individual secondary manifold, thereby offer a particularly large active surface, and, at the same time, a compact construction of the cooling radiator.

In this connection, it is also preferred if at least the upper primary manifold, preferably also the lower primary manifold, has a rectangular cross section, preferably with a dimension of 20×80 mm cross-sectional surface area. It is furthermore extremely preferred if at least the upper primary manifold, preferably both the upper and also the lower primary manifold, are at one end of the individual secondary manifolds, and thereby doesdo not hinder the air stream that flows through the cooling radiator along the submodules, particularly from top to bottom. Simply by the placement of the upper primary manifold at a spacing from the center of the individual secondary manifolds toward their end it is possible to achieve a documented 38% improvement in the air entering toward the cooling radiator and the air exiting from the cooling radiator.

A preferred embodiment provides for a prefabricated construction of the cooling radiator, in which the upper and the lower primary manifold are extend longitudinally and, viewed over their length, have any desired number of openings that lie at a spacing from one another and that are oblong holes in the case of oval tubes as the cooling element, adapted to the shape and provided transverse to the longitudinal expanse. The cooling elements are inserted into openings of individual secondary manifolds connected with the upper and the lower primary manifold, to form a submodule; these tubes, and preferably also the primary manifolds, possess a rectangular or square format. The submodules, which consist of the upper and the lower individual distributor with the inserted cooling elements, are connected in oil-tight manner with the primary manifolds, preferably laser-welded, with their individual secondary manifolds running transverse to the primary manifolds and standing in a flow connection, with one of their openings, with an opening of the primary manifolds, specifically in such a manner that the primary manifolds bridge the submodules disposed transversely to them, either centrally or preferably offset to the side and toward the ends of the individual secondary manifolds.

BRIEF DESCRIPTION OF THE FIGURES

The invention will be described in greater detail below, with reference to eight figures in which preferred embodiments of the invention are shown. In the figures:

FIG. 1 is a front view of a cooling radiator according to the invention,

FIG. 2 is an end view of the cooling radiator of FIG. 1,

FIG. 3 is a top view of the cooling radiator of FIGS. 1 and 2,

FIG. 4 shows an individual secondary manifold for a cooling radiator according to the invention,

FIG. 5 is a section through a primary manifold of a cooling radiator according to the invention,

FIG. 6 is a section through a tube of a submodule in a first embodiment,

FIG. 7 is a section through a tube of a submodule in a second embodiment,

FIG. 8 is a perspective view of a cooling radiator according to the invention in a view from above.

DETAILED DESCRIPTION OF THE FIGURES

FIG. 1 is a front view of a completely assembled cooling radiator 1 prepared for installation on and removal from a transformer. The cooling radiator 1 comprises an upper primary manifold tube 2 and a lower primary manifold tube 3, which can be connected with the transformer (not shown) by flanges 2 a and 3 a in order to be able to form a closed oil circuit with the transformer.

A plurality of submodules 4 that extend into the plane of the drawing, perpendicular and transverse to the longitudinal orientation of the primary manifold tubes 2 and 3, in each instance, are connected between the upper primary manifold 2 and the lower primary manifold 3. The submodules 4 in turn have individual secondary manifolds 5 are connected fluid-tight with the primary manifold tubes 2 and 3 and the tubes of the submodules 4, in order to guarantee passage of cooling medium such as oil through the entire cooling radiator 1. Finally, respective sensors 20 and 21 are connected with the upper primary manifold 2 and the lower primary manifold 3 in order to record both the volumeflow amount and the entry and exit temperature of the cooling medium through the cooling radiator 1.

FIG. 2 shows the cooling radiator 1 from FIG. 1 in a side view from the right, and thereby shows the front or first submodule 4. A multiplicity of these submodules 4, disposed one following the other with air in between, are connected between the upper primary manifold 2 and the lower primary manifold 3 to form the cooling radiator 1 from FIG. 1. It can be seen from looking at FIGS. 1 and 2 together that the cooling radiator 1 and its submodules 4 each formed by oval tubes 6 in the illustrated embodiment (see FIG. 6), can have ambient air flowing around them over their entire outer surfaces. The heated cooling fluid (oil) that flows in from the consumer in the direction of the upper arrow of FIG. 1 is thereby cooled in a particularly effective manner on its way downward. There, the cooling fluid goes back to the consumer (boiler; active part of the transformer) in the direction of the lower arrow. The cooling radiator 1 can be connected with the consumer, if necessary with the interposition of conduits, by the flanges 2 a and 3 a of the primary manifolds 2 and 3.

FIG. 3 shows the cooling radiator 1 from FIGS. 1 and 2 in a view from above. The submodules 4 with the cooling elements inserted into the individual secondary manifolds 5 extend transverse and perpendicular to the upper primary manifold 2, and are bridged by the primary manifold 2 lying in the centers of the submodules 4. In this connection, the submodules 4 each consist of five of the tubes 6 connected at each end to a common individual secondary manifold 5 of essentially rectangular cross section. Once again, a spacing 22 for passage of cooling air through the individual submodules 4 is provided between the tubes 6.

FIG. 4 shows an individual secondary manifold 5 as an individual unit, from its side having openings 23. A fluid-tight and gas-tight connection of the individual secondary manifold 5 to tubes (not shown) for passage of the cooling medium takes place through the openings 23.

FIG. 5 shows a primary manifold 2 as an individual unit, from its side having openings 24. Connection and gas-tight and fluid-tight welding of the upper primary manifold 2 to the individual secondary manifolds 5 (not shown) takes place through the openings 24.

FIG. 6 shows a cross section through a tube 6 having an essentially rectangular cross section and rounded corners. Longitudinally extending ribs 7 are provided equidistant from one another on the outside of the tube, at least on the longitudinal sides of the tube 6 so as to increase the active surface of the tube 6 and thus the contact surface of the tube 6 with the ambient air that flows around the tube 6. Furthermore, an inner partition 8 is provided within the tube 6 to stabilize the tube 6.

FIG. 7 shows a second embodiment of a tube 6 according to the invention as part of a submodule of a cooling radiator according to the invention. The tube 6 once again has an essentially rectangular cross section with rounded corners, with cooling ribs 7 are disposed at the same spacing from one another on each longitudinal side of the tube 6. The height of the ribs 7, thereby their expanse from the outside of the tube 6 toward the outside, is the same over the entire circumference of the tube 6, in order to thereby create uniform heat transfer conditions over the entire tube 6. Inner partitions 8 a and 8 b are provided to stabilize the tube 6 and to divide its cross section into three chambers that have essentially the same size, which walls extend over the entire length of the tube 6.

Finally, FIG. 8 shows a perspective total view of a cooling radiator 1 according to the invention in a view from above. The cooling radiator 1 has an upper primary manifold tube 2 and a lower primary manifold tube 3, with each of which eight individual secondary manifolds 5 are connected. These individual secondary manifolds 5 in turn are connected with seven tubes 6, over whose entire length longitudinal ribs 7 extend. In order to guarantee air passage of the cooling air through the cooling radiator 1 essentially without hindrance, both the upper primary manifold 2 and the lower primary manifold 3 are disposed offset from the centered placement on the individual secondary manifolds 5 (see FIG. 3), toward the ends of the individual secondary manifolds 5.

Reference Symbol List  1 cooling radiator  2 upper primary manifold  2a flange  3 lower primary manifold  3a flange  4 submodule  5 individual secondary manifold  6 tube  7 longitudinal ribs  8 inner partition 20 sensor 21 sensor 23 opening in the individual secondary manifold 24 opening in the primary manifold 

1. A cooling radiator comprising an upper and a lower primary manifold as well as at least one submodule composed of cooling elements that are connected with the upper and with the lower primary manifold via individual secondary manifolds, the submodules each having tubes that are each provided with external ribs, wherein the submodules extend perpendicular and transverse to the longitudinal direction of the primary manifolds, and the tubes of the submodules are set at a spacing from and parallel to one another, for air passage.
 2. The cooling radiator according to claim 1, wherein at least the tubes of the submodules made of aluminum or an aluminum alloy.
 3. The cooling radiator according to claim 1, wherein each submodule comprises up to twelve ten tubes.
 4. The cooling radiator according to claim 1, wherein the tubes of the submodules have a flattened generally rectangular cross section with rounded corners.
 5. The cooling radiator according to claim 1, wherein the tubes have at least one inner partition.
 6. The cooling radiator according to claim 1, wherein the width of the tubes is up to 130 mm.
 7. The cooling radiator according to claim 1, wherein the spacing between the tubes, per submodule, is up to 30 mm.
 8. The cooling radiator according to claim 1, wherein the tubes each have at most 15 longitudinal ribs.
 9. The cooling radiator according to claim 8, wherein the longitudinal ribs have a height of up to 15 mm.
 10. The cooling radiator according to claim 8, wherein the spacing between the longitudinal ribs, relative to one another, is up to 25 mm.
 11. The cooling radiator according to claim 1, wherein up to ten submodules are provided in the cooling radiator.
 12. The cooling radiator according to claim 1, wherein the width of the cooling radiator is up to 540 mm.
 13. The cooling radiator according to claim 1, wherein the height of the cooling radiator is from 0.5 to 3.60 m.
 14. The cooling radiator according to claim 1, wherein the flow-through amount of oil through the cooling radiator is up to 2700 kg/h.
 15. The cooling radiator according to claim 1, wherein the energy dissipation by the cooling radiator is up to 38.00 kW/h.
 16. The cooling radiator according to claim 1, wherein at least the upper primary manifold has a rectangular cross section with a dimension of 20×80 mm.
 17. The cooling radiator according to claim 1, wherein at least the upper primary manifold ( ), preferably both the upper and also the lower primary manifold is at one end of the individual secondary manifolds.
 18. A radiator comprising: a longitudinally elongated and horizontal upper primary manifold; an elongated lower primary manifold below and parallel to the upper primary manifold; respective upper and lower secondary manifolds attached to confronting lower and upper sides of the upper and lower primary manifolds, extending horizontally transversely to the upper and lower primary manifolds, and spaced longitudinally along the respective upper and lower manifolds; respective groups of cooling tubes of flattened generally oval shape connected between each of the upper secondary manifolds and the respective lower secondary manifold and spaced within the groups transversely of the upper and lower primary manifolds for through flow of a fluid to be cooled from the one of the primary manifolds to the respective secondary manifolds, then through the cooling tubes to the other secondary manifolds and out through the other primary manifold, the tubes being spaced longitudinally and transversely from one another; and respective arrays of vertical and transversely extending ribs on each of the cooling tubes.
 19. The radiator defined in claim 18, wherein each of the tubes is of a section elongated perpendicular to the upper and lower primary manifolds.
 20. The radiator defined in claim 19 wherein the ribs are only provided on flat generally planar side faces that extend perpendicular to the upper and lower primary manifolds and parallel to the upper and lower secondary manifolds, and the ribs extend perpendicularly only from the side faces. 